Petroleum-distillation process



May 15, 1923. 1,455,437

V. T. GILCHRIST PETROLEUM DISTILLATION PROCESS Filed July 9. 1918 A TTORNE YS Patented May ll5, 192.3.

i troleum by two or more cuts and only ru'n-v UNITED STATES PATENT OFFICE.

VINCENT T. GILCHRIST, OF SAN FRANCISCO,CALIFORNIA,- .ASSIGNOR TO SUPERIOR PROCESS REFINING'COMPANY, OF SAN. FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

Application med'Juiy 9,

1o all whom t may concern.'

Beit known that I, VINCENT T. GILCHRIST, a citizen of the United States, and a residentl of the city and county of San Francisco, State of California, have made a new Aand useful inveutiom'to wit: vImprovements in Petroleum-Distillation Processes; and'I do hereby declare the following to be a full, clear, and concise description of the same. l

The inventionrelates particularly to a process for removing a high proportion of the lighter grade high gravity products, such as gasoline from crude petroleum.

Among the objects of this invention are to accomplish these results without deleterious results on the quality of the tops removed or the residuum remaining, for further distillation to fuel oil or asphalt.

In this specification and the annexed drawings the invention is illustrated in the form considered' 'to be the best, but it is to be understood that the invention is not limited to such form because it may be em-v bodied in other forms,'-a'nd it is alsov to be understood that in and by the claims following the description it is desired to cover thel invention in whatever form it may be embodied.

It has been the practice heretofore to remove the tops fromthe original crudepe ning the first cut for the lighter gravity commodity and then combining the bottoms or residuums of the first cut top with the second cut tops, and running that for the next heaviest .commodity and so on, for as many commodities as are required.

Tops may be defined as the condensate from crude naphtha first removed from crude petroleum by distillation, and according to this vprocess it is from these tops that the final volatile finished commodities are obtained by re-distillation.

My im roved process of distilling gasoline or ot er derivatives from petroleum consists of, first removing from the crude petroleum all of the tops possible, consistent with keeping the residuum at the required gravity; and then from the total volume of tops removed from the crude petroleum;

to next take-off the gasoline or therlightest gravity of condensates required; to then take from the bottoms or residuums of the tops taken'- 0H the next heaviest lrequired PETROLEUM-DISTILLATION PROCESS.

1918. -Serial No. 244,032.

condensate or commodity, this to'be repeated for as many times as required.

An apparatus of more or less conventional design may be used incarrying outthis process, such a form being indicated in the drawings in Fig. 1, which is a diagrammatic representation of a series of stills and relfractionating columns available in the practice of this process.

Fig. 2 is a diagrammatic chart illustrating the steps and the sequence in the practice of'this invention.

In detail the construction' illustrated in the drawings includes: The crude still 1 set within thefurnace 2, heated bythe burner 3. From the dome 4 of the vcrude still 1 the tops are carried through the pipe 5 into the bottom of the fractionating columns 6, which may be of any standard or special design, from which the vapors are carried over through the pipe 7 into the condenser 8 and issue from the pipe 9 in 'the form of gasoline or the first final fractionation. The reflux from the fractionating column 6 drains downward through the pipe 10 into the first re-run still 11 set within the suitably heated furnace l2. Any residual condensates from within the first re-run still 11, not given off from the still- 11 as the desired first finalfractionation pass out through the pipe 11 into the second re-run still 13 set Within the suitably heated furnace 14. The temperature of the furnaces 2, 12 and 14 progressively rises in the order named. Vapors from the second re-runl still -13 rise through the refractionating column 15 and are carried over through the pipe 16 into the condenser 17 and pass therefrom through the vipe 18 as the second final fractionation.

he reflux from the refractionating column 15 drain back through the pipe 19 and reenter the second re-run still 13. From the second re-run' still 1 3 the unva'porized bottoms pass out through the pipe 20 to additional stills for further fractionation, or use as fuel distillate in accordance with the.

extent to which it is desired to carry the loo` . difference of not less than 125 F. betweenA type of dephlegmating and refractionatingi column; the proportions and `designs of the columns must be such as will give forth the lightest condensate cuts with a temperature the temperature of the oil or tops being run and the vapor of the condensate at the condenser inlet; that is to say, the temperature between the rerun still 1l and the outlet pipe 7 in a first condenser should not be less than 125 F. Commodities or condensates of heavier gravity than 56 Baume, specific gravity equal to 0.7527 to 0.7547, would require a greater temperature difference than 125 F. to distill off the maximum possible volume, but the minimum allowable temperature di'erence' has been determined for gasoline only and this' description relates thereto. Subjecting the tops to a higher temperature before the lighter gravity constituents have been removed, is contrary to the usual practice, and it is thought to be injurious to do so; but I have discovered and demonstrated that it is entirely practicable to subject the whole volume of tops to temperatures at least double that at which gasoline would be distilled off, were the distillation made without dephlegmation, and this can be done without injury, that is without cracking either the condensates given off or the residuum v remaining. Another condi'- tion found to be very essential in increasing the volume of the required fractionatesor condensates being removed, is to make the total volume or percentage of the first tops such as will have a content of not more than 30%- of the first or lightest gravity condensate or commodity to be removed. The greater the percentage or volume of the bottoms the greater Will be the amount of refractionation and separation of the desired commodity. To illustrate: If the percentage of gasoline or other desired commodity indicated by a laboratory test, either a Lebel-Henninger 'or' similar still head is about twenty percent of the original volume for which the distillation is made, itis possible to remove a volume about fifty percent greater than the laboratory indication, equal to about thirty percent of the original; while if the indicated content by the laboratory method is forty percent` of the original, the possibleincrease in volume of take off drops to about fifteen percent or about forty-sixv percent of the original. If the indicated content by the laboratory method is as much as seventy percent of the original tops about a five percent increase'in volume is all that can be gained. Naturally if the distillation `were carried to 100% basis, any method would give the same result.

I eithertake 0E all the top in one cut, or if the volume is such that two,or more cuts are necessary, the several cuts would be blended into one, and the total blended volume run for the commodity of lightest gravity desired. Then rerunning the total volume 0f bottoms or residuum from the cut for the commodity of next heavier gravity, and so on for as many commodities asare required.

IIaving thus described my invention, I claim and desire to secure by Letters Patent is:

1. Ihe process of .distilling petroleum consisting in heating the same; flowing the distilled vapor derived therefrom through a'suitable refractionating column; directing said vapor into a condenser; reheating and revaporizing the reflux condensate from the refractionating column; flowing the resulting -vapor back into the said column; and directing said resulting vapors into said condenser.

2. The 4process of distilling petroleum consisting in heating the same; flowing the distilled vapor derived therefrom through a suitable refractionating column; directin@r said vapor into a condenser; reheating and revaporizing thereflux condensate from the 4refractionating column; flowing the resulting vapor back into said column and combining the same with the first mentioned vapors and condensing said residual vapors; and passing the residuum from said refractionating column into a secondary reheating and revaporizinglrefractionating column.

3. A process` of distilling petroleum consisting in heating the same; flowing the distilled vapor derived therefrom through a suitable refractionating column; directing said vapor into a condenser; reheating and revaporizing the reflux condensate from the refractionating column in a primary still; flowing the resulting vapor back into said column and directing said resulting vapors into said condenser; passing the residuum from said primary still.4 into a secondary still; heating said residuum flowing the distilled vapor derived therefrom through a secondary refractionating column; and directing said vapor into a condenser.

In testimony whereof, I have hereunto set my hand at San Francisco, California, this 2nd day of July, 1918.

VINCENT 'r GiLcHRrsT. y

In presence of:-

BALDWIN VALE, LINCOLN V. JOHNSON.

what y 

